[ siks-teen-moh ]
/ ˈsɪksˈtin moʊ /

noun, plural six·teen·mos.

Also called sextodecimo. a book size (about 4×6 in.; 10×15 cm) determined by printing on sheets folded to form 16 leaves or 32 pages.
a book of this size. Symbol: 16mo, 16°


printed, folded, or bound in sixteenmo; sextodecimo.

Origin of sixteenmo

First recorded in 1840–50; sixteen + -mo Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for sixteenmo

  • Other sizes occasionally used are called “sixteenmo” or “sextodecimo,” “eighteenmo” or “octodecimo,” etc.

    The Story of Books|Gertrude Burford Rawlings

British Dictionary definitions for sixteenmo

/ (ˈsɪksˈtiːnməʊ) /

noun plural -mos

Also called: sextodecimo a book size resulting from folding a sheet of paper into 16 leaves or 32 pages, each one sixteenth the size of the sheetOften written: 16mo, 16°
a book of this size
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012